Generally, the cogeneration apparatus include: an engine as a power source; a power generator drivable by the engine to generate electric power; a heat exchanger (i.e., exhaust heat exchanger) for exchanging heat from the engine; a soundproof housing accommodating the engine, power generator and exhaust heat exchanger; an air inlet or intake port provided in one side wall of the soundproof housing for introducing air into the soundproof housing; an exhaust outlet or discharge port provided in another side wall of the soundproof housing for discharging exhaust (gas) from the engine; and a ventilation fan for sucking in air from the air intake port. A motor section for the ventilation fan is cooled directly by the air sucked in through the air intake port. One example of such cogeneration apparatus is disclosed in Japanese Patent Application Laid-Open Publication No. HEI-11-200951 (hereinafter referred to as “patent literature 1”), which can prevent overheating of the motor section provided for the ventilation fan.
Also known are cogeneration apparatus which include: a housing that is an exterior component; a partition wall partitioning or comparting the interior of the housing substantially into two compartments, i.e. a large compartment and a small compartment; a fuel battery provided in the large compartment; and an inverter provided in the small compartment. The cogeneration apparatus of this type further include: an air intake port provided in the small compartment: a communication opening provided in the partition wall for communicating between the small compartment and the large compartment; an exhaust discharge port provided in the large compartment; and a ventilation fan provided in the exhaust discharge port, and air sucked in through the air intake port is discharged through the exhaust discharge port via the communication opening. One example of such cogeneration apparatus is disclosed in Japanese Patent Application Laid-Open Publication No. 2009-43526 (hereinafter referred to as “patent literature 2”), which can efficiently cool the inverter and fuel battery.
The cogeneration apparatus disclosed in patent literature 1 can also be installed indoors if the exhaust discharge port is provided to project outdoors. Further, the cogeneration apparatus disclosed in patent literature 2 is a fuel-battery type cogeneration apparatus which includes the inverter and the fuel battery as its main components, and which can be installed indoors if arrangements are made for appropriately handling water and carbon monoxide produced from the fuel battery.
However, with the cogeneration apparatus, which includes as its main components the engine, power generator and exhaust heat exchanger and which are installed indoors, it is necessary to install the engine in an airtight chamber in order to prevent exhaust gas from flowing out from the engine to the interior of the housing, and, besides, it is difficult to positively cool the power generator.